. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. STATOCYST RESPONSE CHARACTERISTICS 223 presumably improving the high frequency response, whereas slow moving cephalopods tend to have relatively large statocysts, thus increasing their low frequency sen- sitivity. As pointed out by Young (1984), the main difficulties in applying this idea to cephalopod statocysts is that the radius of curvature can only be approximated as the cross- sectional diameter of the statocyst, and there is only rarely a canal-like structure in the statocyst formed by the an- ticrista and hamuli. In
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. STATOCYST RESPONSE CHARACTERISTICS 223 presumably improving the high frequency response, whereas slow moving cephalopods tend to have relatively large statocysts, thus increasing their low frequency sen- sitivity. As pointed out by Young (1984), the main difficulties in applying this idea to cephalopod statocysts is that the radius of curvature can only be approximated as the cross- sectional diameter of the statocyst, and there is only rarely a canal-like structure in the statocyst formed by the an- ticrista and hamuli. In addition, although there are rec- ognizable patterns of anticristae and hamuli in different groups of cephalopods, it is unclear how these projections affect the flow of endolymph. Clearly, we need a more realistic model of how the endolymph flows within the statocyst. and how this is influenced by the various mor- phological features of the statocyst. Cupula parameters Other morphological features likely to effect the fre- quency response and sensitivity of the statocyst angular acceleration receptor system are the size, shape, and at- tachment of the cupulae. The cupulae are gelatinous, flap- like structures, projecting towards the middle of the stato- cyst, and attached to the crista ridge along the whole length of a segment. The cupulae however, appear to be irregular in shape, often being much taller in the center of the crista segment than at the edges; this is particularly prominent in the squid, Allolcul/iis (Fig. 3a). The center of the cupula will therefore present a much greater area of resistance to endolymph flow than the edges and hence, unless the cu- pula is very rigid, will more easily stimulate the underlying hair cells. This likely differential sensitivity in different parts of a single crista segment may be a method of frac- tionating the sensitivity range of the system. In Octopus this is even more pronounced (Fig. ). Here, the nine crista segments have
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
